Nouns ending in -té are usually feminine.
The suffix marks an abstract quality.
Is santé masculine or feminine?
lasanté
The rule behind it
91.3% of -té nouns are feminine
In context
Avant tout, je prends soin de ma santé.
Above all, I take care of my health.
Une bonne santé est plus importante que tout.
Good health is the most valuable of all things.
Rien n'est plus important que la santé.
Nothing is more important than health.